Web splicing method

ABSTRACT

A method of splicing the trailing end of a processed or spent web to the leading end of a new web by making a &#39;&#39;&#39;&#39;V&#39;&#39;&#39;&#39; cut in both webs, overlapping the cut ends, applying adhesive, pressing the ends together, curing the adhesive and then grinding off the excess material so that the thickness of the spliced area is substantially the same as the thickness of the web.

United States Patent 1 1 1 1 3,874,968 Robinson 5] Apr. 1, 1975 WEB SPLICING METHOD 3.508989 4/1970 Lawrence etal. [56/154 I 3,567,555 3/1971 Stenzenberger et al. 156/509 X [75] ;Z' coatesv'llev 3.575.759 4/1971 Pasquinelli 156/159 [73] Asslgnee: sg gfi'gfg pz Corporauon Primary Examiner-William A. Powell Attorney, Agent, or Firm-Edward .l. Sites, Esq. [22] Filed: Aug. 29, l973 [2]] Appl. No.: 392,727

[57] ABSTRACT [52] US. Cl 156/154 156/59 iar A method of splicing the trailing end ofa processed or [5]] [m B32) 31/00 B3 if 5/00 spent web to the leading end ofa new web by making [58] Field 01';;;ci;1IIII'i11""156/153 154 157 159 a w" l verlapping 156/266 304 6 3 plymg adheslve, pressing the ends together, curing the 242/58 adhesive and then grinding off the excess material so that the thickness of the spliced area is substantially [56] References Cited the same as the thickness of the web.

UNITED STATES PATENTS 6 Claims, 12 Drawing Figures 3.l25 477 3/1964 LaLiberte l56/l54 SIZE 3 WEB SPLICING METHOD This invention relates to a method of splicing the leading edge of a new web to be processed to the trailing edge of a processed or spent web.

The invention has principal utility in joining webs of fibrous material such as paper having relatively small thickness as compared to width and length. A web of the kind in question, by way of example, may be 36 inches wide, one-sixteenth inch thick and hundreds of feet in length, the web being wound in a roll of about 6 feet in diameter. Such webs are utilized in continuously operating, high speed processes. Typical processes and webs are found in conventional asphalt shingle manufacture. While reference is made to webs for shingle manufacture, it will be apparent as the description proceeds that the invention finds utility in a broad range of analogous applications.

The principal object of the invention is to provide a method for splicing webs of the kind mentioned wherein the splice is compatible both physically and dimensionally with the connected webs and particularly with the process in which the web is used.

More specifically, the invention contemplates a method for making a splice which has the same width as the web. substantially the same thickness as the web and which, except for a thin film of adhesive, is of the same material as the web.

The invention provides several important advantages and among these are: (a) the material in the splice area is usable in the process for which the web is adapted so that the problems in finding and discarding a splice are eliminated; (b) the splicing operation can be done by using hand tools and a semi-skilled operator by automatic or semiautomatic equipment; and (c) the splice, being of substantially the same thickness as the web, minimizes likelihood of cutting, forming, handling or stacking equipment used in subsequent processing being fouled up.

The invention will be described below in connection with the following drawings wherein:

FIG. 1 is a diagrammatic view of web processing equipment used in asphalt shingle manufacture;

FIGS. 2, 3 and 4 are diagrammatic views illustrating steps in the method of the invention;

FIG. 5 is a diagrammatic view taken through the center of a joined web for explaining the manner in which material is removed by the grinding rolls;

FIG. 5a is a fragmentary sectional view of the spliced web, the material having been removed from the overlapped area;

FIG. 6 is a diagrammatic view to illustrate the general form of the material removed at the overlapped area;

FIG. 7 is a diagrammatic view used in conjunction with FIG. 5 for explanatory purposes;

FIGS. 8 and 9 are diagrammatic views illustrating different degrees of overlap; and

FIGS. 10 and 11 are diagrammatic views illustrating other ways of practicing the invention.

In FIG. 1, typical apparatus for practicing the invention includes, for example. a roll supply station 1, a splice station 2, a grind station 3, and a processing station 4. The web is generally indicated at W. The web is of conventional form, being flat, elongated with parallel edges and is adapted to be moved in translation along its longitudinal axis A (FIG. 2).

The roll supply station I has means for supporting a roll 5 being processed, a new roll 6 in readiness to be substituted for the roll 5 together with a spent roll receiver 10 adapted to support the spent roll 5' during the splicing operation. Ordinarily, the webs on the rolls are of the same material and have the same physical dimensions.

The splice station 2 is equipped with a work table 11 and web hold downs in the form of rolls l2 and 13 together with manual or automatic tooling for making the desired cuts, overlapping the cut ends, applying adhesive, pressing the ends together and curing the adhesive. The rolls l2 and 13 are mounted to be raised and lowered manually or automatically.

The grind station 3 principally includes a pair of driven, cylindrically shaped grinding rolls l4 and 15 which can be adjusted to suit the thickness of the web together with suitable guide rolls l6 and 17. The axes of the rolls l4 and 15 are parallel and co-planar. The rolls each have a grinding surface functionally com patible with the particular material forming the webs. The axes of the rolls are normal to the longitudinal web axis A.

The processing station 4 includes drive means for moving the web in translation and mechanism for treating the web in accordance with the particular manufacturing operation. The processing station also includes play-out or festooning equipment which functions to provide a reservoir of web which can be used in the processing while the trailing edge of the web is stopped for a splicing operation.

The splicing operation will be explained below.

Assume first that the supply of web from the roll 5 is nearly exhausted and that it is necessary to use a new or fresh roll such as the roll 6. The play-out equipment at the processing station 4 is conditioned to provide a supply of web for processing while the trailing end or portion of the web between the station 4 and roll 5 is stopped.

When the trailing end is stopped, the roll supply station 1 is activated so that the roll 5 is deposited on the receiver 10 (as indicated at 5). The roll 6 is moved up to occupy the former position of the roll 5.

With the trailing end of the spent roll 5' on the table 11, the leading end of the new roll 6 is threaded under the hold-down rolls l2 and 13 until the ends occupy the position as indicated in FIG. 2. The section 18 of the leading end between the rolls l2 and 13 is pressed down into contact with the section 19 of the trailing end so that both the sections are firm against the table 11 with their respective side edges flush. The axis A-l of the leading end 18 and the axis A of the trailing end 19 are aligned so that they are co-planar or in essence co-axial. The hold-down rolls l2 and 13 are brought down to hold the webs while cutting operation for forming the splice is made.

The preferred cut is V-shaped or in the form of a chevron as indicated by the dotted lines 20 in FIG. 3.

The web sections are simultaneously cut so as to minimize the time the web is stopped. A manually operated tool such as a blade knife, a roll knife or even scissors is caused to engage and sever the webs.

After cutting, the hold-down roll 12 is lifted and the roll 5' on the carrier 10 is wound backwards to draw the severed end 19 away from the table 1]. The other hold-down roll 13 is lifted and the portion of the leading end 18 under the roll 13 is removed and discarded.

As noted in FIG. 3, the above leaves the leading end 18 with a V or chevron type cut 21 and the trailing end 19 with a corresponding V or chevron type cut 22. In FIG. 3, the ends 18 and 19 are shown as slightly separated for purposes of clarity.

The cut 21 is symmetrical with the axis A. The apex extends from a point 23 on the axis A to a point 24 intersecting one edge of the web while the other side extends from the point 23 intersecting the opposite edge of the web at 25. The points 24 and 25 are co-planar and lie in a plane which is normal to the axis A. Also, the points 24 and 25 are axially spaced from the point 23.

Similarly, the cut 22 extends from a center point 26 respectively to the edge intersection points 27 and 28 and is symmetrical with the axis A. The points 27 and 28 are also co-planar in a plane normal to the axis A and are axially spaced form the center point 26.

It should be noted that in both the cuts 21 and 22, the apex is shown as a point. It will be understood that in making cuts, particularly with hand tools, the apex may be more rounded in shape. Where this is done, the curved apex is generally symmetrical with respect to the axis A. The V of each cut points in the direction of movement M of the web.

After the cuts are made as above described, an adhe sive is applied for joining the leading and trailing ends together. Normally, this is done by applying adhesive to the trailing end 19 in an area consistent with the amount of overlap. For example, in FIG. 3, the ends are to be overlapped between the cut edge 22 and the dotted line 30 and the adhesive is applied in this area. The adhesive is applied by conventional methods such as by brushing, rolling or pressurized nozzle. Preferably, an adhesive such as thermosetting resin No. 2353 manufactured by Paisley Products Co. is used.

After the adhesive has been applied, the leading end 18 is moved up over the adhesive area and with the side edges of the webs aligned, the leading end is brought down in firm contact with the adhesive. The splice is then heated and rolled so as to make sure of a firm contact, to vaporize any water or solvent and to cure the resin. This makes a joined web. The foregoing con dition is illustrated in FIG. 4 wherein the overlapped leading and trailing ends form a splice within the overlapped area 31 extending between the apex 23 and the intersection points 27 and 28. The V-shaped joint or splice 32, of course, has twice the thickness of the joined web.

The next step in the process is to remove excess material from the leading and trailing ends on the opposite sides ofthe overlapped area so that the overlapped area has a thickness which is substantially the same as the thickness of the joined web. It will be understood that minor variations in overlap thickness are tolerable. For example, in shingle manufacture where the web thickness is 60 mils a variation ofi mils is perfectly tolerable.

The material is removed by moving the joined web along its longitudinal axis so that the overlapped area passes between the grinding rolls l4 and 15. Parenthetically. it is to be noted that the grinding rolls I4 and are normally spaced away from the web so that the same is free to travel without contacting the rolls l4 and 15. However, for the grinding operation, the rolls l4 and 15 are brought into position wherein they are spaced apart the same distance as the thickness of the joined web. The guide rolls 16 and 17 position or cause the pulling force for moving the web to act in a plane which bisects the pass of the grinding rolls.

In FIG. 5, I have diagrammatically illustrated the positions of the leading end 18, the trailing end 19 and the spliced or overlapped area 31 with the web about to enter the roller pass. When the overlapped area is moved into and through the roller pass, the material 34 on the leading end 18 is removed by the top roll 14 and the material 35 on the trailing end 19 is removed by the bottom roll 15. The removed material is diagrammatically illustrated in FIG. 6 where the material to be removed on the leading end is indicated by the phantom lines 34 while the material to be removed on the trailing end is indicated by the phantom lines 35. In FIGS. 5 and 5a the numerals 37 and 38 represent the top and bottom surfaces of the overlapped area after removal. Note that the thickness in the overlapped area is substantially the same as the thickness of the web.

For purposes of illustration in FIG. 7, I have shown the leading end 18 and a trailing end 19 in side by side relationship with areas 34 and 35 represented by the shaded lines. The overlapped area 31 extends between the lines 40 and 41 as noted. The line 42 extends in the center of the overlap. The numerals in FIG. 7 designate the same parts as the corresponding numerals in FIG. 4.

Referring back to FIG. 5, it would appear that when the web enters the roll pass the top roll 14 would simply grind off the leading end 18 so that the web would either be severed or be thinned down beyond practical use. However, the shape of the leading and trailing ends and their relative orientation with respect to the axes of the rolls 14 and 15 produce unit forces on opposite sides of the web which cause the overlapped area to assume positions or move vertically with respect to the plane of the web as it enters the roller pass so that the material areas 34 and 35 are ground off in a manner whereby the overlapped area 31 has a thickness substantially the same as the thickness of the web. This is explained following:

The absolute forces of the roller 14 and 15 on the web are equal or balanced in a vertical direction. Due to the shape of the spliced area and its orientation with respect to the roller axes the vertical unit forces on the opposite sides vary in a manner to achieve the grinding objective.

Referring to FIGS. 5 and 7, as the web enters the pass the top roll contacts the edge 23 and the unit force developed is maximum. The lower roll 15 contacts the bottom surface of the trailing end 19 in a line contact (along line 41 of FIG. 7) and is minimum as compared to the force at 23. This contemplates maximum depth of grinding on the top area 34 and minimum depth of grinding on the bottom area 35 which is the immediate grinding condition. With further longitudinal motion of the web. the unit forces tend to orient the overlapped area counterclockwise so that there is less depth of grind by the top roll 14 and more depth of grind by the bottom roll.

With continued entry of the web into the pass the contact of the roll 14 changes to progressively larger line contacts (along lines 41a. 41b. etc.) with consequent reduction in unit force until such time as the web has entered the pass so that both the top and bottom roll are working on the area represented by the line 42 wherein the unit forces and the depths of grind are the same. As the portion of the web between the line 42 and 40 goes through the pass, the unit forces on the end 19 increase over the forces on the end 18 which is a necessary condition for greater depth of grind on the end 19 and less on the end 18.

When the overlapped area exits from the pass. the spliced web is completely formed; i.e.. the new and spent webs joined together with the proper thickness in the overlap area. This is illustrated in FIG. 5a. The thickness of the overlap area is substantially the same as the thickness of the joined web.

Not only is the chevron shape advantageous as above expressed, but it is important in avoiding transverse motion of the web the overlapped area goes through the grinding roll pass. This is attributed to the bias of the chevron shape developing reaction between the rolls and the web which results in balancing of transverse components. As a consequence, there is a lateral stabilization effect on the web and it tends to be centered in the pass.

The amount of the overlap and the axial distance be tween the apex point and the edge intersections can be selected to obtain a variety of grinding conditions.

Thus with reference to FIGv 7 mentioned above it will be seen that the overlap provides for the symmetrical bias or V-shape to have its effect both as the overlapped area enters the rolls and also as the area leaves the rolls.

Another typical condition is shown in FIG. 8 wherein the leading end is noted at 45 and the trailing end at 46. In the area bounded by the lines 47 and 48, the top roll is working on transverse sections which are less than the full width while the bottom roll I5 is working on transverse sections which are the same as the full width. In the area between the lines 47 and 49, both the top roll and the bottom roll will simultaneously be working on transverse areas which are less than the full width of the web. In the area bounded by the lines 49 and 50, the top roll will be working on the full width while the bottom roll will be working on less than the full width.

In the above instance. one or the other or both of the rolls are always working on bias areas.

The third condition is illustrated in FIG. 9 wherein the leading end is indicated at 51 and the trailing end is indicated at 52. In the area bounded by the lines 53 and 54, the top roll will be working on a transverse area which is less than the full width while the bottom roll will be working on the full web width. Between the lines 53 and 55, however, both rolls will be working on areas which span the full web width. Between the lines 55 and 56 the top roll will be working on a transverse area spanning the full width. while the bottom roll will be working on transverse areas which are less than the full width.

Thus in the condition of FIG. 9. the bias effect takes place during the lead in, is momentarily discontinued and then comes back into play as the web moves out of the roll pass.

In FIG. 10. I have illustrated a modification in the orientation of the cuts to form the splice. A web 60 is spliced at 61. The cut 62 in the leading end 63 and the cut 64 in the trailing end 65 are oriented so that both of the V-shapes point in a direction opposite to the direction ofthe movement ofthe web as noted by arrows M-Z.

In FIG. 11. I have illustrated an alternative cut and roller orientation used in practicing the invention.

A web 67 has a leading end 68 and a trailing end 69. A cut 70 in the leading end extends full across the width of the web and is oriented at 45 to the longitudinal axis A-3. The cut 71 in the trailing end 69 extends full across the width of the web and is oriented at 45 to the axis A3. The cut 70 is parallel to the cut 71. The rotational axes of the grinding rolls 72 and 73 are both oriented at 45 to the axis A-3 or at to the cuts 70 and 71. In the method illustrated in FIG. 11, the same unit pressures for causing a vertical shift and the same transverse balancing pressure as described heretofore will be present on the web.

I claim:

1. The method of splicing the trailing end of a spent web and the leading end of a new web comprising the steps of:

in the leading end of the new web. making a severing cut extending from edge to edge and oriented with respect to the longitudinal axis of the new web and discarding the severed piece;

in the trailing end of the spent web, making a severing cut extending from edge to edge and oriented with respect to the longitudinal axis of the spent web and discarding the severed piece;

applying adhesive adjacent to and along the cut end on at least one of the webs;

overlapping the leading and trailing ends and pressing the same together;

treating the adhesive so that the adhesive bonds the ends together and makes a joined web;

spacing a pair of grinding rolls respectively on opposite sides of the joined web so that the overlapped area can be passed therebetween, the spacing being the same as the thickness of the joined web orienting the axes of the rolls with respect to the longitu dinal axis of the joined web;

passing the overlapped area between the rolls by moving the joined web along its longitudinal axis, the cuts in the leading and trailing ends having been oriented respectively with relation to the longitudinal axis of the joined web and the axes of the rolls also having been oriented with relation to the longitudinal axis of the joined web so that in said passage the rolls develop unit forces on the over lapped area to cause the same to shift in a direction normal to the plane of the web whereby the rolls remove material respectively from the opposite sides of the overlapped area so that the thickness of the area is substantially the same as the thickness of the joined web.

2. The method of splicing the trailing end of a spent web and the leading end of a new web of the same width and thickness as the spent web, the new and spent webs being elongated and having the parallel edges. the method comprising the steps of:

in the leading end of the new web, making a severing cut extending from edge to edge and oriented with respect to the longitudinal axis of the new web and discarding the severed piece;

in the trailing end of the spent web, making a severing cut extending from edge to edge and oriented with respect to the longitudinal axis of the spent web and discarding the severed piece;

applying adhesive adjacent to and along the cut end on at least one of the webs;

aligning the longitudinal axes of the new and spent webs, overlapping the leading and trailing ends and pressing the same together;

treating the adhesive so that the adhesive bonds the ends together and makes a joined web;

spacing a pair of grinding rolls respectively on oppo site sides of the joined web so that the overlapped area can be passed therebetween, the spacing being the same as the thickness of the joined web and orienting the axes ofthe rolls with respect to the longitudinal axis of the joined web:

passing the overlapped area between the rolls by moving the joined web along its longitudinal axis, the cuts in the leading and trailing ends having been oriented respectively with relation to the longitudinal axis of the joined web and the axes of the rolls also having been oriented with relation to the longitudinal axis of the joined web so that in said passage between the rolls: (a) the reaction between the rolls and the overlapped area causes the web to tend to be centered in a transverse direction in the roll pass, and (b) the rolls develop unit forces on the overlapped area to cause the same to shift in a direction normal to the plane of the web whereby the rolls remove material respectively from the opposite sides of the overlapped area so that the thickness of the area is substantially the same as the thickness of the joined web.

3. The method of splicing the trailing end of a spent web and the leading end of a new web of the same width and thickness as the spent web each web being elongated and having parallel edges, the method com prising the steps ot:

in the leading end of the new web, making a pair of severing cuts respectively extending from a point on the longitudinal axis of the web respectively to opposite edges of the web, the intersections of the cuts with the respective edges being co-planar and axially spaced from said center point and discarding the severed piece;

in the trailing end of the spent web making a pair of severing cuts respectively extending from a point on the longitudinal axis of the web respectively to opposite edges of the web, the intersection of the cuts with respective edges being co-planar and axially spaced from said center point and discarding the severed piece;

applying adhesive adjacent to and along the cut end on at least one of the webs;

aligning the longitudinal axes of the new and spent webs. overlapping the leading and trailing ends and pressing the same together;

treating the adhesive so that the adhesive bonds the ends together and makes a joined web;

spacing a pair of grinding rolls respectively on opposite sides of the joined web so that the overlapped area can be passed therebetween, the spacing being the same as the thickness of the joined web and orienting the grinding rolls with their axes parallel and extending normal to the longitudinal axis of the joined web; and

passing the overlapped area between the rolls by moving the joined web along its longitudinal axis to remove material from opposite sides of the overlapped area whereby the thickness of the overlapped area is substantially the same as the thickness of the joined web.

4. The method of claim 3 wherein each pair of cuts is in the form V."

5. The method according to claim 4 wherein the cuts are made so that the V end in each web is oriented in the direction of movement of the web.

6. The method of splicing the trailing end of a spent web and the leading end of a new web of the same width and thickness as the spent web, each web being elongated and having parallel edges, the method comprising the steps of:

in the leading end of the new web, making a severing cut extending across the web at an acute angle to each edge and discarding the severed piece;

in the trailing end of the spent web, making a severing cut extending across the web and at an acute angle to each edge and discarding the severed piece;

applying adhesive adjacent to and along the cut end on at least one of the webs;

aligning the longitudinal axes of the new and spent webs, overlapping the leading and trailing ends and pressing the same together;

treating the adhesive so that the adhesive bonds the ends together and makes ajoined web with the cuts being parallel;

spacing a pair of grinding rolls respectively on opposite sides of the joined web so that the overlapped area can be passed therebetween, the spacing being the same as the thickness of the joined web and orieriting the rolls with their axes parallel and extending at an acute angle to the longitudinal axis of the joined web; and

passing the overlapped area between the rolls by moving the joined web along its longitudinal axis to remove material from the opposite sides of the overlapped area whereby the thickness of the overlapped area is substantially the same as the thickness of the web. 

1. The method of splicing the trailing end of a spent web and the leading end of a new web comprising the steps of: in the leading end of the new web, making a severing cut extending from edge to edge and oriented with respect to the longitudinal axis of the new web and discarding the severed piece; in the trailing end of the spent web, making a severing cut extending from edge to edge and oriented with respect to the longitudinal axis of the spent web and discarding the severed piece; applying adhesive adjacent to and along the cut end on at least one of the webs; overlapping the leading and trailing ends and pressing the same together; treating the adhesive so that the adhesive bonds the ends together and makes a joined web; spacing a pair of grinding rolls respectively on opposite sides of the joined web so that the overlapped area can be passed therebetween, the spacing being the same as the thickness of the joined web orienting the axes of the rolls with respect to the longitudinal axis of the joined web; passing the oveRlapped area between the rolls by moving the joined web along its longitudinal axis, the cuts in the leading and trailing ends having been oriented respectively with relation to the longitudinal axis of the joined web and the axes of the rolls also having been oriented with relation to the longitudinal axis of the joined web so that in said passage the rolls develop unit forces on the overlapped area to cause the same to shift in a direction normal to the plane of the web whereby the rolls remove material respectively from the opposite sides of the overlapped area so that the thickness of the area is substantially the same as the thickness of the joined web.
 2. The method of splicing the trailing end of a spent web and the leading end of a new web of the same width and thickness as the spent web, the new and spent webs being elongated and having the parallel edges, the method comprising the steps of: in the leading end of the new web, making a severing cut extending from edge to edge and oriented with respect to the longitudinal axis of the new web and discarding the severed piece; in the trailing end of the spent web, making a severing cut extending from edge to edge and oriented with respect to the longitudinal axis of the spent web and discarding the severed piece; applying adhesive adjacent to and along the cut end on at least one of the webs; aligning the longitudinal axes of the new and spent webs, overlapping the leading and trailing ends and pressing the same together; treating the adhesive so that the adhesive bonds the ends together and makes a joined web; spacing a pair of grinding rolls respectively on opposite sides of the joined web so that the overlapped area can be passed therebetween, the spacing being the same as the thickness of the joined web and orienting the axes of the rolls with respect to the longitudinal axis of the joined web; passing the overlapped area between the rolls by moving the joined web along its longitudinal axis, the cuts in the leading and trailing ends having been oriented respectively with relation to the longitudinal axis of the joined web and the axes of the rolls also having been oriented with relation to the longitudinal axis of the joined web so that in said passage between the rolls: (a) the reaction between the rolls and the overlapped area causes the web to tend to be centered in a transverse direction in the roll pass, and (b) the rolls develop unit forces on the overlapped area to cause the same to shift in a direction normal to the plane of the web whereby the rolls remove material respectively from the opposite sides of the overlapped area so that the thickness of the area is substantially the same as the thickness of the joined web.
 3. The method of splicing the trailing end of a spent web and the leading end of a new web of the same width and thickness as the spent web, each web being elongated and having parallel edges, the method comprising the steps of: in the leading end of the new web, making a pair of severing cuts respectively extending from a point on the longitudinal axis of the web respectively to opposite edges of the web, the intersections of the cuts with the respective edges being co-planar and axially spaced from said center point and discarding the severed piece; in the trailing end of the spent web, making a pair of severing cuts respectively extending from a point on the longitudinal axis of the web respectively to opposite edges of the web, the intersection of the cuts with respective edges being co-planar and axially spaced from said center point and discarding the severed piece; applying adhesive adjacent to and along the cut end on at least one of the webs; aligning the longitudinal axes of the new and spent webs, overlapping the leading and trailing ends and pressing the same together; treating the adhesive so that the adhesive bonds the ends together and makes a joined web; spacing a pair of grinding rolls respectively On opposite sides of the joined web so that the overlapped area can be passed therebetween, the spacing being the same as the thickness of the joined web and orienting the grinding rolls with their axes parallel and extending normal to the longitudinal axis of the joined web; and passing the overlapped area between the rolls by moving the joined web along its longitudinal axis to remove material from opposite sides of the overlapped area whereby the thickness of the overlapped area is substantially the same as the thickness of the joined web.
 4. The method of claim 3 wherein each pair of cuts is in the form ''''V.''''
 5. The method according to claim 4 wherein the cuts are made so that the ''''V'''' end in each web is oriented in the direction of movement of the web.
 6. The method of splicing the trailing end of a spent web and the leading end of a new web of the same width and thickness as the spent web, each web being elongated and having parallel edges, the method comprising the steps of: in the leading end of the new web, making a severing cut extending across the web at an acute angle to each edge and discarding the severed piece; in the trailing end of the spent web, making a severing cut extending across the web and at an acute angle to each edge and discarding the severed piece; applying adhesive adjacent to and along the cut end on at least one of the webs; aligning the longitudinal axes of the new and spent webs, overlapping the leading and trailing ends and pressing the same together; treating the adhesive so that the adhesive bonds the ends together and makes a joined web with the cuts being parallel; spacing a pair of grinding rolls respectively on opposite sides of the joined web so that the overlapped area can be passed therebetween, the spacing being the same as the thickness of the joined web and orienting the rolls with their axes parallel and extending at an acute angle to the longitudinal axis of the joined web; and passing the overlapped area between the rolls by moving the joined web along its longitudinal axis to remove material from the opposite sides of the overlapped area whereby the thickness of the overlapped area is substantially the same as the thickness of the web. 